The present invention relates to a method for the storage or transportation of an erythritol solution. More particularly, the present invention relates to a method for the storage or transportation of erythritol as food not in the form of crystal powder but of a solution with preventing contamination and deposition of crystals.
Erythritol is a sugar alcohol having 4 carbon atoms and is used widely in food industry as a sweetener having various characteristics such as a degree of sweetness of about 70% of that of sucrose, low energy property, and non-cariogenic property.
Conventionally, the storage (preservation) and transportation (distribution) of erythritol is practiced in a state where usually 20 kg of dry crystal powder as a unit is filled in a paper bag.
In recent years, erythritol has been put in use by beverage manufacturers and the demand therefor has been expanded remarkably. After purchase of erythritol, the beverage manufacturers as mass consumers open a large number of 20-kg bags one by one and throw the crystal into a solution tank to dissolve it before use. However, according as the consumption amount increases, there have arisen undesirable problems from the viewpoints of not only operation but also energy consumption and environmental protection. For example, labor and time required for opening the bags become overmuch. And since erythritol remarkably absorbs heat when it is dissolved, it is hard to dissolve, so that generally it is necessary to dissolve erythritol by stirring and heating with a considerable amount of dissolution energy (concretely with steam) with a use of a solution tank with a stirrer mounted. Furthermore, a considerable numbers of empty bags are treated as wastes.
The present inventors have made various studies in pursuit of erythritol product that is free of the above-mentioned defects. As a result they have found out that various problems on the storage, transportation or the like as described above can be overcome by maintaining erythritol in the form of a solution under given conditions. The present invention is based on this finding.
That is, the present inventors have made a study on the method for supplying erythritol to consumers by converting erythritol to a solution in a stage of shipment and storing or transporting it in the form of solution with studying conditions where no microorganism grow and the product will not deteriorate by coloring with heat or the like, more specifically storage temperature and erythritol concentration.
More specifically, they have studied on the conditions of storage temperature and concentration under which no microorganism will grow, conditions of storage temperature and concentration under which no erythritol crystal will precipitate and conditions of storage temperature under which no coloring of solution will proceed and studied the parameters that satisfy these three conditions.
As a result, they have found out parameters that satisfy them and created a method for the storage or transportation of erythritol in the form of a solution.
The present invention relates to a method for the storage or transportation of an erythritol solution comprising maintaining an erythritol solution under conditions of a solid content of 30% or more and a temperature of 50xc2x0 C. or more, preferably a solid content of 50 to 70% and a temperature of 50 to 75xc2x0 C., and more preferably a solid content of 50 to 58% and a temperature of 55 to 65xc2x0 C., such that no erythritol crystal precipitates.
Erythritol is produced by fermentation of glucose as a raw material using a microorganism having an erythritol producing ability. Erythritol in the fermentation liquid is then subjected to a purification process, more specifically the steps of cell separation, chromatographic separation, ion exchange resin treatment, activated carbon treatment, crystallization, crystal separation, and drying to produce a product of a crystal powder.
It is preferable that in the above process, the erythritol solution of the present invention is produced by concentrating the liquid being subjected to an activated carbon treatment before crystallization to a predetermined concentration, that is, a solid content of 30% or more, desirably from 50 to 70%, and more desirably from 50 to 58%.
The erythritol solution of the present invention may also be produced by adding water to the crystals after crystal separation to dissolve them to a predetermined concentration.
In the present invention, the erythritol solution prepared so as to have a predetermined concentration is maintained at a temperature that does not cause crystal precipitation, can prevent the growth of microorganism and causes no deterioration of product due to coloring, i.e., about 50xc2x0 C. or more, usually from 50 to 75xc2x0 C., preferably from 55 to 65xc2x0 C.
The present invention is a method for the storage or transportation of an erythritol solution comprising maintaining the erythritol solution at a concentration and a temperature within given ranges. Setting up such conditions enables long-term storage of an erythritol solution and transportation of erythritol to the destination in the form of a solution.
The erythritol solution is poured in a tank, for example a tank trailer or a freight car, and is stored or transported to the destination by means of keeping warm if necessary so as to prevent the precipitation of crystal.